Efficacy of secondary isoniazid preventive therapy among HIVinfected Southern Africans: time to change policy?

  • Gavin J Churchyard Aurum Health Research,Welkom, Free State and London School of Hygiene and Tropical Medicine, London
  • Katherine Fielding London School of Hygiene and Tropical Medicine, London
  • Salome Charalambous Aurum Health Research,Welkom, Free State
  • John H Day Aurum Health Research,Welkom, Free State and London School of Hygiene and Tropical Medicine, London
  • Elizabeth L Corbett London School of Hygiene and Tropical Medicine, London
  • Richard J Hayes London School of Hygiene and Tropical Medicine, London
  • Richard E Chaisson Johns Hopkins University, Baltimore, USA
  • Kevin M De Cock London School of Hygiene and Tropical Medicine, London
  • Babara Samb Institut National de la Santé et de la Recherche Médicale, France
  • Alison D Grant London School of Hygiene and Tropical Medicine, London

Abstract

Objective. To determine the efficacy of secondary preventive therapy against tuberculosis (TB) among goldminers working in South Africa.
Design. An observational study.
Methods. The incidence of recurrent TB was compared between two cohorts of HIV-infected miners: one cohort had received secondary preventive therapy with isoniazid and the other had not.
Setting. Health service providing comprehensive care for goldminers.
Participants. 338 men received secondary preventive therapy and 221 did not.
Main outcome measure. Incidence of recurrent TB.
Results. The overall incidence of recurrent TB was reduced by 55% among men who received isoniazid preventive therapy (IPT) compared to those who did not (incidence rates 8.6 and 19.1 per 100 person-years respectively, incidence rate ratio 0.45; 95% CI 0.26 – 0.78). The efficacy of isoniazid preventive therapy was unchanged after controlling for CD4 count and age. The number of person-years of isoniazid preventive therapy required to prevent one case of recurrent TB among individuals with a CD4 count < 200/µl and ≥200/µl was 5 and 19, respectively.
Conclusion. Secondary preventive therapy reduces TB recurrence: the absolute impact appears to be greatest among individuals with low CD4 counts. International TB preventive therapy guidelines for HIV-infected individuals need to be expanded to include recommendations for secondary preventive therapy in settings where TB prevalence is high. Southern African Journal of HIV Medicine Vol. 5(3) 2004: 8-16
Published
2005-06-28
Section
Articles

Journal Identifiers


eISSN: 2078-6751
print ISSN: 1608-9693